The military inadequacies of the ARVN and unpopularity of the Thieu regime should not have been surprising to American officials. American military involvement in Vietnam had escalated precisely because of the weaknesses of the ARVN and previous South Vietnamese governments. In the early 1960s President John F. Kennedy supported the South Vietnamese dictatorship of Ngo Dinh Diem and encouraged the ARVN to fight the Communists without American help. An unpopular Catholic in a nation of Buddhists, Diem used the ARVN as a personal guard; they performed terribly in the field. In 1963 the ARVN was routed in the battle of Ap Bac; that summer anti-Diem riots broke out around the country. Earlier, in an attempt to shore up the regime, Kennedy had increased military assistance; in fall 1963 he authorized a military coup against Diem, whose own generals murdered him on 2 November 1963; President...